Energy capture from the wind is not only a pollution-free resource, but also a means to help reduce dependence on foreign oil. Significant effort has been undertaken by government and industry on large wind turbine systems because of their intrinsic high efficiency. Considerably less attention has been focused on smaller wind systems that can be placed on the roofs of buildings. The reasons for this are many but typically include the unsightliness of large blade wind turbines, the noise generated by these wind turbines, the vibration imparted to the roof structure and the hazards to birds.
There remains a need for a small wind turbine device for homes, commercial buildings, barns, and storage sheds that can capture the benefits of the increased wind speed produced by gabled roof buildings that are also not visually or audibly offensive. A gabled roof is a type of sloped roof in which the two halves of the roof meet to form a peak. There is also a need for wind power production right in the population centers that can reduce the line losses from remote wind turbine farms, eliminate the need for massive investment in new high voltage power lines and puts energy production in the hands of consumers.
Several systems have been disclosed as prior art that place the wind turbine on the ridge of gabled roofs to take advantage of the wind speed acceleration across the roof. These systems have serious flaws in the positioning of the wind turbine and in the design of the airflow channel, which significantly degrades potential performance. Recent studies conducted by the U.S. National Renewable Energy Laboratory (NREL), by Watson et al (“Estimating the Potential Yield of Small Building-mounted Wind Turbines”) and Lubitz (“Effect of Roof Slope on a Building-Mounted in Turbine”) have provided a more comprehensive understanding of airflow across roofs.
US Patent Application Publication No. 2007/0258806 provides an excellent summary of wind turbine design, features, benefits and disadvantages. Several published patents including U.S. Pat. No. 6,948,905, U.S. Pat. No. 7,315,093, U.S. Pat. No. 7,276,809 and published applications including US Patent Application Publication 2007/0210585, US Patent Application Publication 2007/0176431 and US Patent Application Publication 2007/0098542 describe in detail wind turbines designed for roof mounting, all of which are hereby incorporated by reference in their entirety.
The present invention solves the flaws of previously disclosed devices and addresses the above needs.